1. Field of the Invention
The present disclosure relates to a light emitting device which includes a flexible substrate member and at least one light emitting element.
2. Background Information
A light emitting device having a plurality of light emitting elements mounted on a flexible substrate member has been proposed. In such a light emitting device, in order to maintain the brightness and directivity etc., each of the light emitting elements are covered with a light-transmissive resin which can exert lens effect (for example, JP H0525749U). In such a light emitting device, in order to curve the flexible substrate member in a direction parallel to the array direction of the electrically conductive pattern, wire-bonding of the light emitting elements is performed in a direction perpendicular to the array direction of the electrically conductive pattern, and thus preventing disconnection of the bonding wires and/or detachment of the light emitting elements at the time of bending/deforming of the flexible substrate member.
The light emitting device described above can realize a wide light distribution by curving the flexible substrate member in a direction parallel to the array direction of the electrically conductive pattern. That is, bending of the flexible substrate member allows altering the direction of the optical axis of each of the light emitting elements to obtain a wider light distribution as the light emitting device. Meanwhile, in the light emitting devices, a reduction in size while achieving a wide light distribution is an important task in the production of the light emitting devices. For example, in the case where an elongated lighting device such as a straight tube type fluorescent lamp to be manufactured, employing the above-described light emitting device for the built-in light emitting device allows arraignment of a plurality of light emitting elements not only in the longitudinal direction of the lighting device but also in the lateral direction of the blight emitting device. Thus, by bending the substrate member, a wide light distribution can be obtained, but it also requires a matrix arrangement of a plurality of light emitting elements which makes it difficult to achieve a reduction in the size of the light emitting device. Also, in light of directions of the optical axes of the plurality of light emitting elements arrayed in the longitudinal and lateral directions in the light emitting devices described above, uneven color emission and brightness of the light emitting device are inevitable.